INTRODUCING PACKET! An Alternative Approach. by Andy Loomis, KE0UL Greeley, Colorado Packet radio is perhaps the most awkward, complicated and slowest method of carrying on a conversation ever invented for amateur radio! Yet we hear others speak of packet as the greatest thing to hit the hobby since the advent of FM repeaters. It seems that almost everyone who ever managed to get a packet signal on the air is excited about it -- some get so enthusiastic about it that they seem to forget that other modes still exist. What gives? If you can't enjoy a conversation using packet radio, what's all the fuss about? The attraction is an old concept called messaging. Packet radio offers us a means to send a message, as short or as long as we wish, to any ham operator in the world, completely error-free, and with no more power or effort than it takes for a local, 2-meter contact. This was the dream of Hiram Percy Maxim himself: to setup a network of relay stations, coast to coast, in order to pass a message from point-A to point-B in the shortest possible time. To this end, he and others with similar interests created the American Radio Relay League. Its original purpose was to establish such a network. Did it ever work? Sometimes. It was crude, it was subject to propagation quirks, it depended on hams actively attending their stations to "pound the brass" and get the job done. Of course, the ARRL quickly spread its interests far beyond the bounds of relaying traffic, so the National Traffic System was born in an attempt to keep the system alive to this day. Now, enter packet radio. As you read this there exists a worldwide network of automatic, unattended relay stations -- operating 24-hours a day -- ready for you to use for only the cost of your own equipment. The network is so vast, so complete and so effective that you only need to make a single contact with a local, 2-meter station to send any message, any length, anywhere! Your message will arrive at its destination exactly as you typed it, guaranteed. Maxim's dream is finally a reality (and the ARRL just announced it is considering dropping the second "R" from its name). Packet radio has revolutionized the messaging aspects of amateur radio forever. Here are just a few examples of what we can do on packet that simply cannot be done using any traditional ham radio mode: 1. You can send a bulletin, readable by every ham in the United States, announcing the old H.T. you have for sale. Or you could list a room full of stuff you're willing to donate to a good cause. 2. You can look up any number of names and addresses from somebody's CD- ROM Callbook in West Virginia without disturbing its owner. 3. You can receive detailed, scientific data on every earthquake in the world for the past dozen days, or get a list of the orbital elements of every interesting satellite circling the globe. 4. You can send some intricate mathematical formulas to your friend in Scotland, without worrying if a plus gets changed to a minus. 5. You can post a bulletin in every town in Germany asking for advice on how to repair your old Grundig short-wave receiver. Packet radio can never replace chit-chat. It's not supposed to. Ham radio has always been a social hobby -- full of conversations about every topic under the sun. Packet is simply not suitable for this type of activity. It can be done, of course, and often is; but you should learn this now: packet's indisputable strength is pushing paperwork. You may be quite disappointed with packet radio if your intent is to use it as just another conversational mode. When you first got your license and tried to use a repeater you had to learn quite a few operating techniques. You needed to learn about offsets, hang-time and courtesy beeps. You had to learn how to operate your radio, how to put "PL" in it and how to make an autopatch call. Packet is no different. There will be a few new things to learn, but no more than what you have already demonstrated you have a capacity for. The secret is to set aside everything you know about normal ham operation! Open your mind to some completely different approaches. Forget offsets, PL and PTT buttons. Forget beams, high power, rag-chewing and QRM. Forget station identification, Q-signals, propagation and signal reports. Packet is none of these. Your HT is exactly as effective on packet as your friend's kilowatt. Your 19" mag-mount antenna perched on the refrigerator is every bit as good as your friend's stacked, 30-element array. If you can hit ANY packet station with a 2-meter FM, full-quieting signal, you can reach the world. Because of the already existing network in place worldwide, it is just as easy to send a message to Australia as it is to send it across town. The network itself "knows" how to route your message. Simply send it to the nearest full-service bulletin-board station in your community. From there, your message may hop through dozens of similar stations, all automatically, until it finally appears on the bulletin-board station in your friend's home town. There, at her convenience, she can pick it up on her own packet station. Generally, the forwarding process takes about an hour for statewide messaging, about a day for North and Central America and two or three days for messages to reach the rest of the world. These figures are average-worst-case. Some messages get through in minutes, others take a bit longer. Packet radio is not fast. True, it uses high- speed data transmission with some fairly complicated, computerized equipment; but the end-to-end equivalent speed belies its sophistication. The beauty of the system, however, is the lack of errors. Because packet is error-free, it makes no difference at all how many "hops" the messages take to reach their destination. At each hop, the message may be placed on "hold" for a few minutes while other traffic is exchanged, then it is sent on its way. For this reason, it takes some time for a message to move through the network. How packet does all this is beyond the scope of this article. The purpose of this article is to explain just what packet has to offer you. There are numerous books which explain the technical aspects of packet radio, but you don't have to learn all the stuff in order to use packet, any more than you had to learn about oscillators and phase-lock loops in order to use your H.T. By far, the most useful thing you can do in order to get the fullest benefit from packet is to become "computer-literate." Learn how to operate a computer (as opposed to learning how a computer operates). Take a course at your community college or just learn-by-doing (playing). Assuming you already own a working 2-meter, FM radio, you will have to get a terminal node controller (called a TNC) and either a computer or a "dumb" terminal. The TNC will cost in the neighborhood of $130, new. Finding a used TNC is just about impossible because no-one wants to sell them once they start using them. The TNC is the device that cross- translates computer language into packet radio language. But you can think of the TNC as a "black-box." You really don't need to know anything about how it works or why it works. But if you're like most hams, curiosity will someday win out and you will learn all about them. The TNC connects between your computer/terminal and your radio. By far the most popular TNC is the PK-88 made by A.E.A. This unit outsells all other brands combined, two-to-one. Other excellent brands are the Kantronics and the MFJ. There are even some "software" TNC's that make use of the computer's own internal intelligence to perform the necessary functions, but they generally require a much more extensive understanding of computers than most packet beginners are willing to learn. Probably the best advice is to use the brand most popular in your area so you can draw on someone's help in the event you have a problem. A computer or terminal, suitable for packet can cost anywhere from $20 to $2,000. If you use a terminal instead of a computer you will not be able to "save" any messages or pre-compose and edit your own outgoing messages. This can be an annoyance but it sure beats not being on packet at all! Terminals are cheap, nowadays. Its hard to find a new one anywhere at a decent price, but the older ones are just fine. Plan to spend from $20 to $50 for a used terminal at any swapfest. Once you are enjoying packet you won't be content to use the terminal forever and will probably end up with a real computer to run things. ALL TNC's will work with ALL popular computers. Usually you will have to make or buy a special cable to attach your computer or terminal to your TNC. The TNC's come with full instructions for making the cable as well as for making the other cable that attaches the TNC to your radio. The next step is to follow the TNC manufacturer's instructions. Read the manual carefully and do exactly what is asked for. You'll be "teaching" your TNC things like your callsign and the callsigns of your favorite bulletin-board stations. You will teach your computer how to "talk" to the TNC. Once you've done this the TNC knows everything else. It knows how to make and maintain your connection to the network. It knows when to transmit, when to listen and when to ID itself. It does everything for you except decide who you are going to send a message to and which messages you want to read. You just sit at the keyboard, type a few strokes and watch the screen! Most packet operators leave their TNC and radio operating around the clock. All TNC's contain a mini-bulletin-board for sending and receiving messages from the nearby hams. The computer is only necessary during the actual times you are typing or reading a message -- it can be used for any other purpose when you aren't using it for packet. The TNC, by itself, will send, receive and store messages even while your computer is turned off! Keep this feature in mind as you consider the overall cost of your packet system. I really hope this article helps shed some light on what packet radio is all about. I would be most grateful for any feedback you care to give. But packet radio can never replace chit-chat. It's not supposed to. Ham radio has always been a social hobby -- full of conversations about every topic under the sun. Packet is simply not suitable for this type of activity. It can be done, of course, and often is; but you should learn this now: packet's indisputable strength is pushing paperwork. You may be quite disappointed with packet radio if your intent is to use it as just another conversational mode. When you first got your license and tried to use a repeater you had to learn quite a few operating techniques. You needed to learn about offsets, hang-time and courtesy beeps. You had to learn how to operate your radio, how to put "PL" in it and how to make an autopatch call. Packet is no different. There will be a few new things to learn, but no more than what you have already demonstrated you have a capacity for. The secret is to set aside everything you know about normal ham operation! Open your mind to some completely different approaches. Forget offsets, PL and PTT buttons. Forget beams, high power, rag-chewing and QRM. Forget station identification, Q-signals, propagation and signal reports. Packet is none of these. Your HT is exactly as effective on packet as your friend's kilowatt. Your 19" mag-mount antenna perched on the refrigerator is every bit as good as your friend's stacked, 30-element array. If you can hit ANY packet station with a 2-meter FM, full-quieting signal, you can reach the world. Because of the already existing network in place worldwide, it is just as easy to send a message to Australia as it is to send it across town. The network itself "knows" how to route your message. Simply send it to the nearest full-service bulletin-board station in your community. From there, your message may hop through dozens of similar stations, all automatically, until it finally appears on the bulletin-board station in your friend's home town. There, at her convenience, she can pick it up on her own packet station. Generally, the forwarding process takes about an hour for statewide messaging, about a day for North and Central America and two or three days for messages to reach the rest of the world. These figures are average-worst-case. Some messages get through in minutes, others take a bit longer. Packet radio is not fast. True, it uses high- speed data transmission with some fairly complicated, computerized equipment; but the end-to-end equivalent speed belies its sophistication. The beauty of the system, however, is the lack of errors. Because packet is error-free, it makes no difference at all how many "hops" the messages take to reach their destination. At each hop, the message may be placed on "hold" for a few minutes while other traffic is exchanged, then it is sent on its way. For this reason, it takes some time for a message to move through the network. How packet does all this is beyond the scope of this article. The purpose of this article is to explain just what packet has to offer you. There are numerous books which explain the technical aspects of packet radio, but you don't have to learn all the stuff in order to use packet, any more than you had to learn about oscillators and phase-lock loops in order to use your H.T. By far, the most useful thing you can do in order to get the fullest benefit from packet is to become "computer-literate." Learn how to operate a computer (as opposed to learning how a computer operates). Take a course at your community college or just learn-by-doing (playing). Assuming you already own a working 2-meter, FM radio, you will have to get a terminal node controller (called a TNC) and either a computer or a "dumb" terminal. The TNC will cost in the neighborhood of $130, new.